@pelson: What enhancement are you suggesting for core cpython? The missing `subprocess` members is not a cpython problem, it's an App Engine problem. I don't know the rationale (why we don't supply stubs that raise `OSError` instead of them simply being missing), but this is fairly consistent across App Engine for modules that are unsupported. I've had a discussion with the Python team about changing this and it would be unlikely, because it could break existing users expectations (for example, they may be catching `AttributeError`). I think for now it would be easier to bring this into matplotlib, if it's not too much trouble. If App Engine ends up changing `subprocess` to include stubs, then it can be removed from Matplotlib.